1. Field of the Invention
The present invention relates to a linked container for transporting precision devices such as IC chips, various electronic devices (for example, connectors, switches, transmitters and the like) and the comparatively small precision parts incorporated in precision machines (herein inclusively referred to as "IC chips"), wherein the IC chips take their individual and discrete places within the container.
2. Description of Prior Art
The important or principal electronic circuits are delivered nowadays in the form of the so-called "chip" in order to improve their operation reliability as well as the efficiency of assembly plants. Thus, the preliminary and/or final assembly lines are supplied with the IC chips which are arrayed in a considerably large transporting container, which has a plurality of chip-holding recesses forming longitudinal and transverse rows. Generally, a robot hand or the like equipped beside one side of a transporting route supplies a IC chips one by one from the large container to the assembly line. Therefore, the robot hand must reciprocate a long distance in order to pick up the IC chip positioned near the other side of the transporting route. Consequently, an average waiting time for the assembly line to receive the individual IC chips becomes long to thereby lower the production efficiency. Further, the robot hand must change its position every time when it picks up the IC chips. In the event that the robot hand fails to grip any IC chip at its correct portion, the IC chip would be broken and the assembly line would be disturbed seriously. In order to avoid such an incident, the position control of robot hand should be so accurate as undesirably raising the control system cost.
It has been already proposed in this industrial field to employ a band-shaped container which comprises a single row of recesses each holding one IC chip. This container advances in an intermittent manner, and a robot hand reciprocates a short distance between the transportation route and the assembly line. The container, which typically is an injection-molded plastics band, has walls of a thickness sufficient to protect the IC chips. As shown in FIG. 16, a bottom defining each recess "f" in the row has a round hole "e" for insertion of an ejector. Small apertures "g" formed along one side of the band are for engagement with a sprocket wheel. This band, wound on a reel in use, has however proved somewhat problematic in a certain point. The phantom lines "C" in FIG. 16 indicate an inevitable curvature remaining in the band unwound from "the reel. In other words, the unwound band cannot take again its absolutely straight position indicated by the solid lines "D". The curled band will cause a misoperation of the robot hand which must exactly pick up the IC chips one by one. If the recess walls were rendered as thin as possible to eliminate such a drawback, then another problem would arise that the band becomes so fragile and is broken when handled, thus failing to afford a sufficient protection to the band. A damaged transporting band will also hinder the IC chips from being picked up in an accurate manner. Another disadvantage inherent in the prior art containers ( here called "trays" ) is that they occupy much space for storage and handling, and require much labor for replacement of some unit trays with new ones. In addition, it is not necessarily easy to supply the unit trays in any desirable linked form. Further, the trays for the IC chips of some kinds have to withstand a necessary baking treatment, thereby raising the manufacture cost of the trays.